Intervals – The Distance Between Notes
Intervals are one of the most important constituent parts of music, in my opinion, and yet many students do not understand what I am talking about when I mention intervals during lessons. This is why I have written this post, to provide an online permanent reference for my private students and anyone else who might be interested. To begin, download the Lesson Sheet below. This sheet is in Bass Clef, but if anyone would like a Treble Clef version, feel free to message me via my Contact Page.
What is an interval?
This is really simple, an interval is just another word for “the distance between two pitches”. Obviously two pitches can be played one after the other (Melodic or Horizontal), or can be played together, at the same time (Harmonic or Vertical). In western music, the smallest interval we have is called a semitone and equals 1 fret up or down from the note you start on, on a bass or guitar. Any other interval is constructed from “jumps” of more than one semitone, for example a Major 3rd is 4 semitones above or below the note you started on, a Tone (or Major 2nd) is 2 semitones.
We can work out how big intervals are by using semitones. As bassists or guitarists, we gauge intervals using fret numbers. If we count the note you begin on as 0, then move up or down by a given number of semitones/frets, we can also say we have moved by a particular interval, given below:
- 0 Semitones = Unison
- 1 Semitone = Minor 2nd
- 2 Semitones = Major 2nd
- 3 Semitones = Minor 3rd
- 4 Semitones = Major 3rd
- 5 Semitones = Perfect 4th
- 6 Semitones = Augmented 4th / Diminished 5th
- 7 Semitones = Perfect 5th
- 8 Semitones = Augmented 5th / Minor 6th
- 9 Semitones = Major 6th / Diminished 7th
- 10 Semitones = Minor 7th
- 11 Semitones = Major 7th
- 12 Semitones = Perfect Octave
There are more names for some of these intervals, and it is also worth doing some reading on Enharmonic Equivalents for further clarification on notes that sound the same but are named or notated differently. Also, for fretted instruments, be aware there is more than one way to play a lot of intervals e.g. a minor third can be 3 frets above the first note on the same string, but also 2 frets behind on the string above. So a C to Eb Minor 3rd interval can be either: 3rd fret to 6th fret on your A string, or 3rd fret A string to 1st fret D string. This is another reason you need to know what all the notes are all the way across the fingerboard.
Intervals in Scales
Everyone has heard of a scale of some description when talking about music, even if it’s people saying “I learned music when I was young and hated playing scales”. This is actually a very common reaction when the dreaded scale is mentioned. In reality, there is nothing to be afraid of. It’s sort of like when you were a kid and you thought there were monsters under your bed at night, it was all really scary until your mum or dad turned on the lights and you realised there was nothing there.
A scale is just a series of intervals played one after the other. The gap between each note in a scale is generally no more than a Tone, although bigger intervals do occur every so often. So, for example, a C Major scale consists of these notes:
C D E F G A B C
And then repeats as it goes up or down. If you look at this in terms of tones and semitones, it goes like this:
The construction of scales and arpeggios etc. will be dealt with in a further lesson which I am currently writing, but in the meantime all you need is to understand that scales and things can be broken down into individual intervals between each note. There are also a finite amount of intervals in the world, some of which are much more commonly used than others.
Describing Intervals by Name
An interval name is broken into two parts: the Quality (Major, Minor, Perfect, Augmented or Diminished) and the Number (2nd, 3rd, 4th etc), giving you all the information you need to work out what the interval is.
The Number is based on something called the diatonic staff position. In other words, the lines and spaces of a musical staff. If we refer to the example staff above containing C Major, we can count the lines and spaces to work out the interval, for example, C to G is a 5th: we can see that C is a 1st, D is a 2nd etc. until G is a 5th. E to G is a 3rd, because E is a 1st, F is a 2nd and G is a 3rd. That’s all there is to working out the number of an interval. Easy!
To my mind, the Quality is the description of the “sound” of the interval. There are only 5 possible options with this: Perfect, Major, Minor, Augmented and Diminished. Once you learn the details of how these work as well, and see a few examples, everything will become a whole lot easier.
Perfect intervals were traditionally considered “perfectly consonant”, so Unison and Octaves are Perfect, as are 4ths and 5ths.
Major and Minor intervals are not considered perfect, and apply to the other, non-perfect numbers. These are the 2nd, 3rd, 6th and 7th. As a rule, the larger interval is always called Major, and the smaller is called Minor.
Augmented and Diminished intervals are either greater or smaller than Perfect, Major or Minor intervals by a semitone, but still have the same interval number because they are on a particular line of the staff. For example, C to E# is an Augmented 3rd, because it has exceeded the major 3rd interval by a semitone. Similarly, C to Gb is a Diminished 5th because it has exceeded a perfect interval by a semitone.
As a rule of thumb:
Major and Perfect Intervals up by one semitone become Augmented.
Major Intervals down by one semitone become Minor.
Minor and Perfect Intervals down by one semitone become Diminished.
Inversions occur when intervals are switched around: either the lower pitch of an interval is raised by an octave, or the higher pitch is lowered by an octave. In my mind, when inverted, intervals become opposite. So:
- 2nds = 7ths
- 3rds = 6ths
- 4ths = 5ths
- Major = Minor
- Augmented = Diminished
- Perfect = Perfect
And, as in mathematics, the equals sign works either way around e.g. C to A: a Major 6th inverts to a Minor 3rd.
Compound intervals are simple in concept as well, and will aid in your understanding of chords and harmony. Once you go past the octave (8th), the numbering of intervals continues. So a Compound 2nd becomes a 9th, a Compound 3rd becomes a 10th, and so on. These are sometimes known as the upper extensions of a chord, and certain extensions/compound intervals are more common than others. I have included these in the Lesson Sheet at the top of the page.
How They Sound
This is the most important thing to me, as knowledge is great but needs to be used in practical situations. If you can learn how intervals sound and how to play them on your instrument, you have the makings of strong relative pitch. When I was younger and I learned all this, I began by working out the shapes of the intervals on the fingerboard and wrote them all out, so I knew how to play them all. I then began memorising how they sound by playing them over and over.
I have since been shown a much better way. Still begin by working out the shapes and writing them down so you know what they are on the fingerboard, but for learning to recognise the sound of each one, I recommend Functional Ear Trainer Basic. This exercise was given to me by my teacher, Joe Hubbard, and his article on using this exercise with the software to develop relative pitch/interval recognition should be read and followed by everyone. Check it out here.
This may seem like a lot of complex stuff to learn, but trust me, once you know it you will be amazed at how much easier it is to play music, by ear or written out. It’s absolutely worth it.
To begin, read this article over and over, and make notes, sit down and work out what all the intervals are, and try the ear training. Also, Google can be a great asset, so if there are things you are unsure of, have a search and read other peoples writings on this subject. Just bear in mind that articles may or may not be wide of the mark, so take all the information on board and try to draw your own conclusions on the subject. The information will also stick in your mind better this way. Finally, if you really want some help or clarification on any of this, a 1 hour lesson with me in person or on Skype will be enough to completely deal with this topic. Feel free to contact me if you would like to do this.
As I keep saying, Knowledge is Power and learning is fun………..so just enjoy the ride, you will definitely get better!